Immortality Cultivation: I Farm in the System Space - Chapter 192 - : The Return of Elder Bai and Elder Yu

Thrown into a brutal world of swords and sorcery, his memories stolen by an unseen force, Magnus wanted only one thing: to go home.But every kingdom, devil, and god — along with regressors, possessors, and fellow reincarnators — seeks to carve him apart.Survival demands war. War demands survival.And with a System that hides more than it reveals, Magnus is dragged down a bloodstained path... one battle, one betrayal, one broken world at a time.

She is an expert in medicine, the only daughter of Yun Tian, Yun Valley’s master.

Her parents died, leaving her alone in this world. She fell from heaven to hell. She had a marriage prospect but her future husband broke it off. The entire world view her as a joke.

She blossoms in Feng Yun Hall, with unparalleled wisdom and startling beauty.

Against all the people eager to make a move, she lifts her hand first. Kill the chicken to warn the monkey.

But nobody knows that the soul within her has long been replaced by someone from another world.

She has no regret in the past life and originally plans to live an idyllic life, but because of the same question from the past life, she gives up the peaceful life and steps into the power struggle for imperial power.

- Description from Novelupdates

Although Leng Ruoxue is born mentally challenged, she is the most beloved granddaughter of the number one general in the Eastern Lake Nation. She is despised by her fiancé and schemed against by her love rival. However, she is reborn as a powerful soul. This is a fantasy world, and also a world where the strong are respected. Cultivation, alchemy, weapon refinement, beast taming—the once foolish young miss has transformed into a stunning genius. Pill refinement and weapon refinement are all child's play. Heaven Grade medicinal pill? Even my pets won't turn an eye to it. Heavenly Treasure? I have the space to grow my own. Sacred artifact? Sorry, that's too low a level. I only know how to refine divine artifacts. Beast taming? My beasts deliver themselves to my doorstep.

A scientific genius named Thomas Harrier was transmigrated to an imperial prince body after a car accident that took his life. He found out that he is in a world similar to our own with a timeline akin to early twentieth century. The body that he is occupying was the imperial prince of a failing empire who suddenly rose to power after a successful assassination attempt of his father. Unaware that the attack is just the beginning of what is to come. He faces many challenges throughout. Will Thomas Harrier be able to live his second life in peace while running an empire and getting it back to its former glory? Or will he succumb into a conspiracy lurking within the country's borders?

Expect some:

Cold war era techs.

Super battleship with advanced electronics, propulsion, and fire control systems?
Helicopters?
Missiles?
Modern medicines and equipment?
AC-130?
A nuke?
Challenger or Abrams or Leopard?
F-4 Phantom or MIG-21?
Colored TV's.

Everything!!!

PS. Cover not mine, I just found it on google.